1. Field of the Invention
The present invention relates generally to concrete weldment connectors and, more particularly, to an improved concrete weld clip for interengaging seam edges of first and second slabs of pre-cast concrete, and in particular for use with pre-fabricated concrete used in deck structures and the like. The weldment connector of the present invention in particular provides an improved construction which permits its use with shallower concrete forms than which is possible with prior art weldments. Additionally, the weldment connector of the present invention includes first and second extending leg constructions which are both rotationally offset and configured to increase and more evenly distribute, across the entire slabs, loading forces applied directly to the seam.
2. Description of the Prior Art
Weldment clips are well known in the art for interconnecting succeeding slabs of pre-cast concrete along a seamed edge. The purpose of such clips (also known as weldments or flange connectors) is to redistribute, into the interior of the concrete slabs, forces directed to the seamed edges (such as by vehicles traveling upon a parking deck structure). In the absence of such weldment clips, the concrete slabs would quickly crack, buckle and fracture along their seam edges.
A first example of such a prior art flange connector is illustrated in U.S. Pat. No. 6,185,897, issued to Johnson et al., and which adjoins adjacent concrete structural members. The flange connector discloses a one-piece steel member having a faceplate, opposing faceplate returns arranged at a 90xc2x0 angle relative to the faceplate, succeeding and flattening bend portions and, finally, substantially planar and extending legs which terminate in perpendicularly configured reinforcing tabs.
The flange connector of Johnson, while disclosing a substantially functional weldment, has been found not to be practical for use with many pre-cast concrete forms of shallower depth and due to the cross sectional height of the front faceplate. Additionally, the construction of the first and second legs extending from the faceplate, and by virtue of the intermediate faceplate returns and flattening bends, have been found in practice to bend or crack under severe loading conditions. Further, the provision of the perpendicularly arrayed and end reinforcing tabs are disclosed as having holes formed therethrough for receiving a flexingly inserted and reinforcing steel bar. However, it has further been found in practice that the bending of such terminating edge portions of the weldment clip legs have the opposite effect of localizing the pressure forces applied along the seamed edge, and opposed to the desired effect of distributing such forces throughout the substantial interiors of the concrete slabs.
A further example of a concrete weldment and method of manufacture is disclosed in U.S. Pat. No. 5,402,616, issued to Klein. The weldment again includes a central plate having a planar, weldable surface along an edge of the concrete slab, the weldable surface being perpendicularly disposed to the horizontal plane of the concrete slab. A pair of outstanding arms extend, in substantially planar fashion, from the weldable surface and are embedded in the concrete slab. The outstanding arms have a constant height across their length and support a steel reinforcing mesh at a predetermined height during the concrete slab casting operation. A blockout is provided to the mold during the casting operation to keep the top edge and front surface of the weldable surface free and clear of concrete and both provides for thermal expansion of the weldable surface to minimize cracking and spalling during welding, as well as being removed (so as to be removable) from the mold after the concrete has hardened.
U.S. Pat. No. 3,958,954, issued to Ehlenbeck, discloses a weldment for embedment along the edges of concrete members and to permit welding joinder of adjacent members. The weldment is formed of sheet steel and includes an elongated central portion which is exposed when the weldment is emplaced. The central portion terminates in fold lines from which extend tapered tails that are embedded in the material. The fold lines are angularly displaced in a generally converging fashion and the tails are bent out of the plane of the central portion.
U.S. Pat. No. 4,930,677, issued to Jolliffee, teaches a concrete connector for a concrete structure and having two generally flat plates connected together along one edge to form an elongated structure having a substantially xe2x80x9cLxe2x80x9d shaped cross section. One plate is sized with an opening to allow unset concrete to flow therethrough and to hold the plate firmly within the concrete when it is set. The other plate protrudes from the set concrete and is available for connection with another and similar such connector by direct welding or clamping of the two plates together.
U.S. Pat. No. 4,724,649, issued to Lowndes, III, teaches another type of side weld plate, similar in respects to that previously described in Jolliffee and which includes an elongated body with a body section embedded in a concrete slab. An interconnecting flange section of the weld plate is positioned adjacent an edge of the concrete slab and so that the flange section provides an exposed weld surface which allows for adjacent concrete slabs also having a side weld plate to be welded together.
The present invention is a weldment connector which is an improvement over prior art connectors in that it permits use with shallower concrete forms than possible with prior art weldments. Additionally, the weldment connector of the present invention includes first and second extending leg constructions which are both rotationally offset and configured to increase and more evenly distribute, across the entire slabs, loading forces applied directly to the seam. The configuration and construction of the extending legs also renders them more resistant to cracking than has heretofore been experienced with other prior art types of weldment connectors.
The construction of parking deck structures, or other suitable concrete supported foundations, is well known in the art and typically includes a suitable pattern or form within which the concrete is poured and set. It is desirable to pre-mount a plurality of individual weldment connectors in spaced apart fashion along one or both of the elongated extending edges of the form and prior to pouring concrete.
Each weldment connector includes a substantially elongated and planar shaped front face having a specified length, width and height. First and second legs are integrally formed with and extend from opposite end locations of the front face. The legs each have a height and thickness substantially equal to that of the front face and extend in both a desired angular orientation relative to an axis extending axially through the front face, as well as extending in a combined axial and rotationally offset fashion so that so that, upon being embedded within a first selected slab of concrete with its front face extending in exposed fashion along its extending edge, the construction of the legs exhibits greater resistance to cracking.
In use, a second weldment connector is likewise embedded within a second selected slab of concrete in similar fashion and so that its corresponding front face extends along an opposing extending edge, in proximate fashion relative to the front face of the first weldment connector. A conventional weldment, such as is provided by an electric weld gun, secures together the front faces of the first and second connectors. In use, the weldment connectors act to redistribute, within the interior body of each concrete slab, load forces applied along its common seamed edge.
An additional feature provided by the weldment connectors of the present invention include the provision of undulated portions at terminating end locations of the first and second legs. The undulated portions create a ripple or billowing effect in the associated legs, the result of which is that they better grip the surrounding concrete (in similar fashion to the bent edges 28 of Johnson U.S. Pat. No. 6,185,897) while at the same time substantially functioning in the desired fashion to direct, within the interior of the associated concrete slab, load forces applied along the seamed and interconnecting edge.